1. Field of the Invention
The invention herein relates to a collapsible hand propelled cart, and more particularly to an improved collapsible cart that is specially suited for moving objects over soft or otherwise yielding terrain such as sand at the beach.
2. Overview of Prior Art
A variety of art exists in the area of hand carts and even as it relates to beach travel, but all fall short of true functionality with respect to the end user. In U.S. Pat. No. 4,865,346 Carlile disclosed a wheeled collapsible cart assembly which includes a foldable lower frame, or bottom shelf, suitable for receiving an ice chest, and a pair of bracket arms extending behind the frame that could be used for placing folding chairs, but no receptacle is disclosed nor anticipated for transporting the many additional items taken to the beach such as blankets, toys, clothes, etc. In addition, the bracket arms are not practical because this storage means requires the chairs to sit on the horizontal portion of the arms. To move the cart the user pulls the handle back, tilting the device back and the chairs would easily fall out. This is exaggerated by the rough terrain this device is intended to travel over.
Carlile's disclosure shows a collapsible feature, but it is not without disassembly of the handle bar and the wheels. Removed parts are clumsy to transport and easily lost when the need to reassemble presents itself. The only functionally foldable portions are the bottom shelf and the bracket arms, but since the latter is lacking in utility, folding has no true advantage. In addition, because this disclosure has the cooler chest as a part of the claimed invention, it does not accommodate the variety of sized and shaped existing coolers or ice chests that individuals already own, not to mention containers other than coolers, such as picnic baskets and the like.
The beach cart as disclosed by Maturo, Jr. et al. in U.S. Pat. No. 3,677,571 has a receptacle for storage of miscellaneous supplies and a hanger for a beach chair, but still falls short of optimal functionality. First, the chair hangers are useful only with the style of chair shown in this art, and even then only for the one chair. When such a device is to be used, it is expected that a larger group, such as one or more whole families, would be using the device and therefore multiple chairs would be needed. Second the folding feature consists of nothing more than collapsing the receptacle by the four bar linkage of the frame. The reduction in overall storage and transport size such as in the car, is minimal. Finally, the wheel as disclosed and claimed is a cylindrical shell with a series of annular members which are supported by a plurality of longitudinal wires. The resultant might provide increased traction if the device was driven by the cylindrical wheel, but it is driven by the handle. The lugged affect of the wheel only increases the rolling friction of the wheel as it is pulled across the sand making it more difficult to use than a smooth wheel that offers minimal work requirement of displacement of sand.
In a similar manner, Bonewicz, Jr. et al. in U.S. Pat. No. 4,887,837 disclosed a pair of wheels that included a plurality of elongated cleats. As previously mentioned, such cleats only inhibit the function of the product. Although the disclosed device does have a folding platform and a bag to store articles, the bag is lacking in a structural support to enable adequate size so as to be truly useful. The folding feature is limited to the support platform and as such does not fold sufficiently to be considered truly collapsible.
Edmonds' utility carrier, as disclosed in U.S. Pat. No. 4,790,559 does show a smooth wheeled foldable carrier for transporting items over terrain such as sand at the beach. The frame supports only an unyielding load box of a size that must match the frame. This could be used to store an ice chest or cooler or as a receptacle for other articles, but not both. It would not be obvious to add structure for transporting additional items such as beach chairs or items that would be stored in a bag such as towels, toys, etc. Though the folding feature does not necessitate disassembly, it is not collapsible and it remains bulky and cumbersome.
In U.S. Pat. No. 4,703,944, Higson disclosed a wheeled beach caddy in the form of a chair. The device does fold, but it does not collapse. The platform folds up to the back, but the folding does not functionally go beyond that point. In addition there is not a receptacle or bag to hold additional items of miscellaneous sizes and shapes. There is a "C-shaped chair rack" to hold beach chairs but if the chairs are positioned completely on top of the rack and supported against the back, the transported chairs would potentially be very unstable, especially while traversing uneven terrain, as with the Carlile patent. The chairs could be hung from the rack, placing them in stable equilibrium and making them more secure. If the chairs could be made to fit on this device, the bottom platform could not be used to store and transfer items, because the chairs would be in the way. It is not obvious to add structure to include a means for carrying a variety of items in a storage bag.
Another alternative design is disclosed in U.S. Pat. No. 4,429,897 by Friedman, et al. Therein the issue of a receptacle for containing miscellaneous items is not disclosed nor anticipated, neither is an additional structure for holding chairs. It does not disclose a folding feature but instead a "slidable, transversely extending back". A potential consideration with such a method includes problems with tolerance build up that can make such a telescoping device difficult to use or even non-functional. Also the environments in which such a device may be used could subject the device to dirt and sand. Such abrasives do not mix well with a telescoping structure because only a small amount of this particulate could cause an interference between such mating parts, making the parts no longer able to slide one on the other. The total size of the device would not be reduced like one that is optimally foldable, thus making it more difficult to store when not in use. Also, the disclosed thin wheels are not suited to traversing sand or other yielding terrain.
Other disclosures include Ward in U.S. Pat. No. 5,197,754 and Crothers in U.S. Pat. No. 4,222,585 where a wheeled cart is disclosed including a receptacle or bag to store miscellaneous items. No bottom frame or platform is disclosed, nor a method for transporting items such as beach chairs. Ward claims a rigid frame which constitutes minimal folding for storage. In a comparable manner, Crothers disclosed a folding of the device but not any breaking of the frame with additional folding features that would make it collapsible, thereby minimizing the needed storage space. Here as disclosed in much of the previous art, the wheels are not suited for traversing sand or other yielding terrain.
Mazzarelli et al. disclosed a beach tote cart in U.S. Pat. No. 3,693,993 which can be used as a cot or lounging chair. The disclosure claims a pair of frames pivotally attached, with a rolling cylinder. No collapsible feature is disclosed. A mesh pocket, or nylon fabric webbing panel, is claimed to be used for storage of items, but it must double as a seat back when the device is used as a lounge chair. This necessitates the capacity of the receptacle to be small in comparison to the size necessary to be truly functional. Also with such a design the items must be strapped in, as is disclosed. This results in an inconvenience to the user. If a supporting shelf or frame and bag type receptacle is made available, tie downs could many times be eliminated.